The World Health Organization says despite continuing efforts against tuberculosis, one-third of the world's population is infected with tuberculosis germs and up to 10 percent of them will become sick or infectious.
Wednesday is World TB Day and the United Nations health body says the number of new cases is still increasing each year in southeast Asia, Africa and the eastern Mediterranean.
The WHO says the disease killed 1.3 million people worldwide in 2008 - most of them in southeast Asia and Africa.
The WHO says drug resistant strains of TB are an area of particular concern. It says one such variety, known as extensively drug resistant TB, has been detected in Bangladesh, India, Indonesia and Thailand.
The organization is also concerned about TB combining with HIV, the virus that causes AIDS. HIV weakens the immune system and makes an infected person much more likely to become sick with tuberculosis.
World Tuberculosis Day is observed on March 24 to commemorate the date in 1882, when the German physician Robert Koch announced his discovery of the bacteria that cause TB.
At that time, tuberculosis, which usually attacks the lungs, was the single biggest disease threat to humanity.